Brominated fatty acid amides



1966 c. R. HALL ETAL.

BROMINATED FATTY ACID AMIDES 2 Sheets-Sheet 1 Filed June '7, 1963 m OE 8 O 0. Om Om 0? Om Om O\| Om mm Om OON 00m 00 009002 OO OOQ OOOM OOON 00mm 000m OOO O ON Om 0% Om Om Ow Om Om OO mN Omw OON 00 Om OOON 00m 00m OO0.00: OOmm OOOM OOO United States Patet fiFice 3,288,822 Patented Nov. 29, 1966 3288822 BROMINATED FATTY ACID AMIDES Charles R. Hall, Akten, hio, and Joseph E. Stenis, Palos Park, Ill., assigners te The C. P. Hall Cempany of Elliuois, Chicage, Ill., a corporation of l1ie Filed June 7, 1963, Ser. Ne. 286,223 14 Claims. (Cl. 260404) This inventon relates te fatty acid amides in which the nitrogen is monoer disubstituted, which amides contain bromine in the nitrogen-substituent portion and which may er may not contain bromine in the fatty chain also. The amiuo group is -meno er disubstituted by a fatty chain er mixture of fatty chains, and at least one substituent is frem an unsaturated fatty acid and is breminated. If the amine group is disubstituted the substituents may be diflerent-one may be substituted with the ether unsubstituted, as when the amine group is from an amine formed from a naturally occurring fatty acid cempesition.

Definitions: In the specification and claims, fatty chain is used to refer to a chain such as is attached te the carboxyl group of a fatty acid, -and fatty amino greup is used te refer to an amno nitrogen group containing one or two fatty chains.

The bromine is introduced by additien so that there is en even number of at least two bromine atoms in each molecule and the number of bromine atoms in any molecule may total as many as 6 er or more.

Thus, the ferrnula may be written 0 R R t N in which R is (1) a fatty chain er (2) a fatty chain containing an even number of bromine atoms per molecule, and NR"R is a brorninated monoer disubstituted amino greup in which there are an even number of bromine atoms.

The breminated amides of this invention are chiefly valuable as flame retardants for use in plastics. Flame retardants should have a bromine content such that when added te a combustible material there is 3 te percent or more of bromine present, based on the weight of the combustible material. They should have at least a boiling point of 250 C. er even 275" C. er 300 C. or more at atmespheric pressure. There are two considerations important in connection with this use. First, the mechanism of the burning process. The large size of the bromine molecule accomplishes the most important function necessary te retard combustion; that is, the absorption of heat energy. It absorbs the heat necessary te prepagate combustion. The second consideration is the physical barrier of the brernine te oxygen penetration. Chlorine does not possess this property te anywhere near the extent that brernine does.

It is important that the amide include at least one N- subsituent. This contributes compatibility te the cempeund so that the compound is compatible with a wide variety of thermoplastic organic polymers, etc. It makes the amides unusually substantive te polartype polymers, thus decreasing their extractability. The amides are stable te heat and light under a wide variety of conditiens. They are also stable te hydrolysis and moisture and are resistant te meld and fungi.

In order te obtain one or more of the foregoing beneficial results te the utmost degree, it is often desirable te utilize an N,N-disubstituted amide. On the other hand, the molar brernine content of an amide is lowered by utilizing a disubstituted amide rather than a monesubstituted amide.

The flame retardants can be added to cellulosic plastics, polyethylene, nylon, polyesters, rubber and other elastemers, films, coatings, spun fibers, plastic moldings, castings, adhesives, and may be ued in the impregnatien of weed, paper, cotten cleth, etc. A brernine content of at least about 25 er 30 percent or more is generally required in a fiame retardant. It may be incorporated di rectly in the plastic prior te spinning or other fabricatien. The brorninated amides are also useful as pigment deflocculants in pants, gasoline additives, 1ubricant additives, insecticides, as insect repellants, pesticides, pest repellants, meldicides, ungicides, drug additives (as for example in the treatment of skin and hair conditions), cosmetics (as for example in the treatment of acne and ether skin disorders), etc. They are synergists and selvents for drugs, insecticides and insect repellants (as for example te increase the potency of DDT, Sevin, N,N-diethyl toluamide, etc. They facilitate the removal of gasses in molten metal processing, and are useful as deemulsifiers, as fire-resistant hydraulic fluids and ether heat-transfer media, anti-blocking agents, meld releases, slimicides, anti-static agents, selubilizers for dyes, antioxidants, antiozenants, and as cutting and drawng compounds. They are useful for the treatment of woods and seeds, and in the treatment of drilling muds, etc.

Their valuable properties include their polarity and outstanding compatibility with organic systems, their freedom from eder, their low vaper pressure, and the fact that the bromine is present in a form that is generally noncerrosive. Most of the brominated amides are liquid, and this facilitates their incorporation in plastics, etc.

The -bromination is efected by brominating carboncarbon double bends of ethylenically unsaturated chains at least one of which double bends is in the N-substituent portion of the molecule (R er R). Bremination adds two bromines at one or more of the double bends, whether these be only in the N-substituent portien er whether some brernine adds te the fatty acid chain also. Bromination is effected by mixture of brernine with the amide in liquid form er in solution where necessary, and catalysts of such additien bromination may be employed but are not necessary. During the brornination it is desira-ble te empley a low temperature te prevent substitution with release of hydrogen bromide.

The compounds which can be brominated vary appreciably in chain length and in unsaturation, and thus the melecular weight and other properties dependent upon chain length can be varied over a wide range, as well as brernine content. Compeunds containing 25 percent or more of brernine are particularly valuable as fiame retardants.

A flame retardant in which the fatty chain (R) is small, as for example, where it is acetyl, butyl er hexyl, is often preferred because of the higher percentage of bromine present in the finished amide. If a longer chain fatty acid is used it is preferably unsaturated and brominated concurrently with the substituent group er groups. A short chain substituent group er groups is desirable, such as allyl, and when the substituent group er greups are allyl, a longer chain fatty acid may be employed in order te produce a less volatile and more permanent product. Because the fatty acids containing 18 and more carbon atoms are particularly abundant in nature, they are preferred in the fatty chain (R) when the substituent (R and R) er substituents are allyl groups, and when one or two lenger chain substituents (R' and R") are desired they are preferably obtained from an unsaturated atty amine which contains 18 or more carbon atems, and the fatty chain of the amide is then preferably derived frem acetic or an unsaturated, naturally occurring fatty acid of 18 or more carbon atoms which is brominated concurrently with brornination of the substituent portion of the molecule.

In the production of flame retardants it is not necessary to carry the brornination of the fatty amides to completion, and then molecules containing an N-substitution of bromine content are mixed with molecules containing an unbrominated N-substitution, or they may be mixed with amides containing cheaper chlorinated substituents. The brominated fatty amides may be mixed with amides containing no bromine obtained from saturated fatty acid with whch unsaturated fatty acid is found in nature.

The amides of the subject invention have one or two N-substituents (R' or R") of which the following are illustratve, the number of carbon atoms in each being indicated:

9,10-dibromostearyl 18 carbon atoms) 12,13-dibromo, 9,10-ley1 (18 carbon atoms) 9,10,12,13-tetrabromostearyl (18 carbon atoms) 9,10-dibromo, l2-hydroxystearyl (18 carbon atoms) 12,13,l5,l-tetrabromooleyl (18 carbon atoms) 9,10,12,1315,l6-hexabromostearyl (18 carbon atoms) 15,16-dibrorno, 9,l0,l2,l3-linoleyl (18 carbon atoms) 9,10-dibrmo arachidyl (20 carbon atoms) 13,14-dibromo, behenyl (22 carbon atoms) dibromo, tetrabromo and hexabromo derivatives of elaeostcaryl (18 carbon atoms) dibromo, etc. derivatives from 5689,11,12,14,15-

eicosatetraenyl (20 carbon atoms) dibromo, etc. derivatives of clupanodonyl (22 carbon atoms) dibromo, etc. derivatives of licanyl (18 carbon atoms) Also, the N-substituent may comprise one or two 2,3-dibromopropyl radicals derived from an amide formed from an allyl amine.

The acids trom which the foregoing brominated amides are obtainable and the number of carbon atoms in each, are:

Oleic, linoleic and linolenic acids (18 carbon atoms) from many fats and oils Ricinoleic acid (18 carbon atoms) from castor oil Erucic acid (22 carbon atoms) trom rapeseed oil Elaeostearic acid (18 carbon atoms) from tung oil Arachidonic acid (20 carbon atorns) clupanodonic acid (22 carbon atoms) from fish fats and oils Licanic acid (22 carbon atoms) trom oiticica oil Such amides include, for example, the N-dibromostearyl and N,N-di(dibromostearyl) amides trom formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palrnitic acid, stearic acid, etc. amides, as well as amides of brominated acids obtained by addition brornination eiected simultaneously with brornination of the one or two nitrogen-substituents, such as dibromolauric acid, dibromomyristic acid, dibromopalmitic acid, dibromostearic acid, tetrabromostearic acid, etc.

Usually there will be two substituents on the nitrogen because a single substituent leaves an active hydrogen. The amide used for the brornination contains at least one unsaturated N-substituent which is brominated (or the substituent may be brominated before incorporation in the amide), and the other N-substituent, if any, may be saturated or unsaturated before the brornination reaction.

The invention is further illustrated by the followinsx examples:

EXAMPLE I This example refers to the preparation of N23-dibromopropyl 9,10-dibromo stearamide which is first obtained in admixture with other brominated amides. The starting material is a technical methyl oleate havng the following composition:

Percent Methyl myristate 3.7 Methyl myristoleate 1.8

Methyl palmitate 5.2 Methyl palmitoleate 6.6 Methyl stearate 0.3 Methyl oleate 75.8 Methyl linoleate 5.6

Five -thousand nine hundred seventy-five pounds of this mixture of methyl esters having an iodine number of 88, a saponification number of 191, and an acid number of less than 2.0 mgs. of KOH per gram, was charged to a 1000-ga110n reaction vessel. The contents of the vessel was heated to 120 C. under a vacuumand agitated to remove the water. After cooling to 40 C., 141 pounds of 25-percent sodium methylate solution in methanol was added and then the addition of 1265 pounds of liquid allyl amine was begun. The addition of amine caused the temperature to rse to about 50 to 60 C. over a period of 8 hours. Agitation was continued for another 8 hours and then the sodium methylate was neutralized with dilute sulfuric acid and the unreacted methanol and excess amine evaporated. The remaining liquid was then filtered and distilled in a molecular still to obtain the N-allyl amide of the mixed acids.

One hundred grams of the amide prepared as above was placed in a 3-ncck flask provided with a stirrer, a thermometer and an inlet funnel through whch bromine was added. Three m1. of methanol was added and mixed with the amide. The flask was cooled to minus 10 C. in a Dry Ice-isopropanol bath. The bromine was then added while maintaining the temperature between plus 10 C. and minus 10 C. until the orange-reddish color due to uncombined bromine persisted. A large amount of heat was evolved in the reaction, and good agitation was employed to dissipate the heat and keep the reaction mixture from forming color bodies. The methanol present suppresses the formation of color bodies and free fatty acids, and aids in maintaining a good color. Other alcohols might be used. The product was then washed with water and then with 5 percent sodium carbonate solution until neutral to phenolphth-alein. Chloroform may be added for separation of the water from the bromo derivative. as sodium hydroxide, sodium bicarbonate, ammonium hydroxide etc.

On purification the product contained 45.84 percent bromine with a specific gravity of 1.4256 at 60 C. reerred to water at 60 C. and 1.4243 at C./70 C. The infra-red spectrum is shown in FIGURE 1.

T0 obtair1 more complete halogenation, the fore-going bromo amide can be chlorinated until saturation of the double bonds in the various molecules of which the composition is composed is substantially complete.

EXAMPLE 11 N -9,1 0-dbromostary lacetamde This example is given to show how the brominated compound can be made when the acyl group is derived from a short chain acid such as acetic. The other examplcs show how they can be derived from a long chain aliph-atic acid.

The starting amide for this reaction is made by acetylation with acetyl chloride or oleylarnine. The oleyl amine is a technical gratie derved from a commercial oleic acid containing approximately percent oleic acid. It is usually produced by dehydration of the commercial unsubstituted amide to form the nitrile, which is theri reduced to the amine, thus,

One hundred grams N-oleylacetamide was dissolved in grams of ethyl alcohol and mixture cooled to 5 Other alkaline solutions may be used such C. Agtation was begun and then bromine was added drop by drop until 50 grams were added to the solution. The appearance -and maintenance of a :reddisl1-orange color showed an excess of bromine was present. This was agitated another 30 minutes while the temperature was allowed to climb to 10 C. Then the mixture was taken up in 1,1,1-trichlorethylene and washed. with warm water, then with 5 percent Na CO (hen with water until the washings were neutral to ltmus paper. The product was stripped of chloroform and other remaining volatiles and the viscous liquid product was analyzed:

Bromine, percent 31.96 Sp. gravity at 70 C./70 C. 1.1969

Infra-red spectra obtained from thick and thin films -are shown in FIGURE 2.

EXAMPLE III N910-dibromstearyl-9J0-dibromostaramde This is an example of a bromo amide in which hoth the acyl chain and the N-substituent are derived from a longchan unsaturated fatty acid. The compound is:

To make this, 44 grams of N-oleyl-oleamide was dissolved in 150 ml. of isopropyl alcohol and the solution cooled to C. Twenty-six grams bromine dissolvcd in 100 ml. of CHCI was added drop by drop while the solution was agitated vigorously. The solution was slightly orange at the end of the reaction. It was then washed with warm water and percent ammonia solution. The subsequent washings to remove base were uncomplcated. The liquid product was stripped to remove isopropyl alcohol, water, and chloroform and then analyzed.

Brornine, percent 26.54

Sp. G. -at 70 C./70 C 1.1234

The infra-red spectrum is shown in FIGURE 3.

EXAMPLE IV NN-di-(Z,3-dibromopropyl) 9,10-dibromostearamzde This example is =gven to show how a compound could have bnomine added to each suhstituent in the amide. 'Ihus, R, R, and R each have an alkylene group to which brornine may be added.

The N,N-diallyl-oleamide can be made hy the usual methods. In this nstance it was made by the reaction of 1 rnole of oleoyl chloride with 2 moles of diallyl amine. This product was dissolved in methanol and bnomnated by the method given in Exarnple I. The product obtained was a viscous liquid which remained liquid despite its high bromine content, in contrast to other hexabromostearamides. Although it too has six atoms of bromine in the molecules it remains a liquid whereas a hexahromide such as N,N-dimethyl hexabromostearamide is a solid. It is more easly incorporated in plastic than other =bromides of similau nature and it is more compati-ble because of its 1ow melting point. Its analysis shows:

Bromine, percent 45.10 Sp. G. at 70 C./70 C 1.4975

'Fhe infra-red spectrum is shown in FIGURE 4.

It is often important to have the suhstituents small in order to not dilute the efiect of the amide group Arnide substitution is important as it increases the ability of the molecule to dissolve or the dissolved by a substance.

Generally, the disubstituted arnde is more compatible than the mono-suhstituted one. Also, lgenerally, the disubstituted amides have 'lovver melting points or can 13e lquids as compared to the mono-suhstituted amides, brominated or not in the acidic part of the chain or in the N-substitution.

Commercially, the use of pure compounds in the preparation of the amides will not be as appealing as the use of mixtures. The mixtures will be derived from naturally occurring fatty acid mixtures which usually will include saturated acids. These fatty chains will add no =bromine during the hromine addition procedure, so the unsatnration of the N-sulbstitution and the extent to which the double bonds are brominated will determne the desired average bromine content which in flan1e retardants, f01 exarnple, will be some 25 er 30 Weight percent or more. Thus, the desired brornne content may 13e ohtained by having a more highly brominated compound present with a dibnorninated or unbrominated a.mide. By bromination of allyl substituents, for examplea high bromine content RII in which R is selected from the class consisting of (1) saturated fatty chains containng 1 to 21 carbon atoms and (2) atty chains of 3 to 21 carbon atoms substituted by an even number of bromine atoms and derived from an initally ethylenically unsaturated fatty chain, and NR'R" is a brominated fatty amino =group in which R is a fatty chain of 3 to 21 carbon atoms and contains an even number of bromines in which R may be such a fatty chain or hydrogen.

2. The compound of claim 1 in which R is methyl.

3. The compound of claim 1 in which R contains 17 carbon atoms.

4. The compound of claim 1 in which R is a saturated fatty chain.

5. The compound of claim 1 in which R is a brominated, naturally occurring fatty chain which contains an even number of bromine atoms.

6. 'I'he oornpound of claim 1 in which R is hydrogen.

7. The compound of claim 1 in which R is a bromin- =ated naturally occurring fatty chain which contains an even nurnher of bromine atoms.

8. The compound of claim 1 in which both R and R contain 18 carbon atoms.

9. The oompound of claim 1 in which -NRR" includes a 2,3-dibrornopropyl group.

10. A brorninated amide composition with a laoiling point of at least 250 C. at atmospheric pressure, which compostion contains at least 25 percent bromine and is composed essentally of an amide having the formula given in claim 1 in which at least one of the groups R and R" contains 18 carbon atoms brominated with an even number of bromine atoms.

11. N-2,3-dibnomopropyl 9,10-dibromostearamide.

12. N9,l0-dibromostearyl acetamide.

13. N-9,l0-dibrornostearyl 9,10di bromostearamide.

14. N,N-di(2,3-dibromopropyl) 9,10-dibromostearamide.

No references cited.

CHARLES B. PARKER, Primary Examiner.

JOSEPH P. BRUST, Examiner.

A. H. SUTTO, Assszant Examiner. 

1. AN AMIDE HAVING THE FORMULA 